Problem: $\left(9x - 6\right)\left(-2x - 9\right) = \ ?$
Solution: $= 9x \cdot \left(-2x - 9\right) - 6 \cdot \left(-2x - 9\right)$ $= \left( 9x \cdot -2x \right) + \left( 9x \cdot -9 \right) + \left( -6 \cdot -2x \right) + \left( -6 \cdot -9 \right)$ $= -18x^2 + \left( 9x \cdot -9 \right) + \left( -6 \cdot -2x \right) + \left( -6 \cdot -9 \right)$ $= -18x^2 + \left( -81x + 12x \right) + \left( -6 \cdot -9 \right)$ $= -18x^2 - 69x + \left( -6 \cdot -9 \right)$ $= -18x^2 - 69x + 54$